Note: Descriptions are shown in the official language in which they were submitted.
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DISR CARTRIDGE HAVING HEAD LOADING/UN~O~nING RAMPS
RELATED APPLICATIONS
This application is related to co-pending U.S.
patent application Serial No. 08/324,895, filed October 18,
1994, entitled "Head Load/Unload and Cleaning in a Data
Storage Device".
R~RG~OUND
Field of the Invention
The present invention relates to disk cartridges
for storing digital information, and more particularly, to a
disk cartridge having head loading/unloading ramps within the
cartridge to facilitate the loading and unloading of
read/write heads onto a storage medium within the cartridge.
Descri~tion of the Prior Art
Removable disk cartridges for storing digital
electronic information typically comprise an outer casing or
shell that houses a disk-shaped magnetic, magneto-optical or
optical storage medium upon which information can be sto~ed.
The cartridge shell often comprises upper and lower halves
that are joined together to house the disk. The disk is
mounted on a hub that rotates freely within the cartridge.
When the cartridge is inserted into a disk drive, a spindle
motor in the drive engages the disk hub in order to rotate
the disk within the cartridge at a given speed. The outer
shell of the cartridge typically has an opening near one edge
to provide the recording heads of the drive with access to
the disk. A shutter or door mechanism is often provided to
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cover the head access opening when the cartridge is not in
use to prevent dust or other contaminants from entering the
cartridge and settling on the recording surface of the disk.
Disk drives for use with such removable disk
cartridges typically employ either a linear actuator
mechanism or a radial arm actuator mechanism for positioning
the read/write head(s) of the disk drive on the recording
surface(s) of the storage medium, or disk. Because the disk
cartridges are designed to be removable from the drive, the
linear or radial arm actuators must be able to move off, and
away from, the storage medium to a retracted position in
order to prevent damage to the head(s) when a cartridge is
inserted and removed from the disk drive.
Many removable cartridge disk drives employ a pai~
of opposing read/write heads for recording and reproducing
information on both sides of a storage medium. Typically,
the opposing heads are disposed on flexible suspension arms
at the distal end of an actuator that allow the heads to fly
closely over the respective surfaces of the rotating disk.
20 The opposing heads must be spread apart as they approach the
edge of the disk during a head loading operation in order to
avoid collision with the edge of the disk. Similarly, when
the heads are unloaded from the disk, they must again be
spread apart to avoid collision with the edge of the disk and
each other.
A mechanism for controlling the loading and
unloading of heads in connection with a linear actuator
mechanism is disclosed in commonly assigned, co-pending
patent application Serial No. 08/324,895, filed October 18,
1994, entitled "Head Load/Unload and Cleaning in a Data
Storage Device". As disclosed therein, wings are attached to
the heads that act as lifters to control the vertical
position of the heads. The wings are in close proximity to
the heads to fully ensure that the motion of the wing is the
35 motion of the heads. The wings ride on opposed ramps fixedly
disposed in the drive as the carriage of the linear actuator
moves toward and away from the disk.
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U.S. Patent No. 4,965,685 (Thompson et al.)
discloses a head loading mechanism for use with a radial arm
voice coil actuator. The radial arm actuator comprises a
bifurcated actuator arm that has upper and lower suspension
arms mounted at its distal end. Magnetic heads are mounted
on the ends of the respective suspension arms. The head
loading mechanism of Thompson et al. comprises an elongate
head load arm that is pivotally mounted within the disk
drive. Ramped prongs are formed at the distal end of the
head load arm. When the disk drive is not in use, the
suspension arms are separated by, and rest upon, the ramped
prongs. When a disk cartridge is inserted into the disk
drive, the actuator arm moves toward the disk cartridge
causing the suspension arms to move down the ramped prongs
and onto the recording surfaces of the storage medium.
U.S. Patent No. 4,683,506 (Toldi et al.) discloses
yet another mechanism for separating a pair of opposing
read/write heads during cartridge insertion and for
subsequently bringing the heads together onto the surface of
a storage medium. Like other prior art mechanisms, this
mechanism is also mounted in the disk drive.
Because the head loading/unloading mechanisms of
the prior art are mounted in their respective disk drives,
they must be designed to account for the relatively loose
tolerances on the positioning of a disk cartridge within the
disk drive. The vertical displacement of the read/write
heads during head loading operations must be sufficiently
large to accommodate worst case vertical positioning of a
disk cartridge within the drive. Unfortunately, such large
30 vertical displacement of the read/write heads adversely
affects other tolerances in the disk cartridge and disk
drive, and the increased vertical travel of the read/write
heads affects the speed of the head loading operation.
Accordingly, there is a need for a more efficient head
loading/unloading mechanism that provides more accurate and
controlled positioning of the read/write heads relative to
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the storage medium within a disk cartridge. The present
invention satisfies this need.
SUMMARY OF THE lNV~NllON
The present invention is directed to a disk
cartridge comprising a disk-shaped storage medium and an
outer casing that houses the storage medium. The outer
casing has a head access opening for provlding access by the
read/write heads of a disk drive to the disk-shaped storage
medium within the casing. Head loading/unloading ramps are
lo provided in the cartridge proximate the head access opening
for loading and unloading the read/write heads of the disk
drive to and from the storage medium. In a preferred
embodiment, the head loading/unloading ramps comprise firs~
opposed ramps that separate the read/write heads as they
approach the storage medium within the casing, and second
opposed ramps that bring the heads together for loading onto
the storage medium in a controlled manner. Placement of the
ramps within the cartridge allows the movement of the
read/write heads to be more accurately controlled in relation
to the vertical position of the storage medium.
The foregoing and other objects, features and
advantages of the invention will become evident hereinafter.
BRIEF DESCRIPTION OF TRE DRAWINGS
The foregoing summary, as well as the following
25 detailed description of the invention, is better understood
when read in conjunction with the appended drawings. For the
purpose of illustrating the invention, there is shown in the
drawings an embodiment that is presently preferred, it being
understood, however, that the invention is not limited to the
specific methods and instrumentalities disclosed. In the
drawings:
Figure 1 is a perspective view of a disk cartridge
in accordance with the present invention; and
Figure 2 is a perspective view of the bottom shell
of the disk cartridge of Figure 1 showing the placement of
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S
head loading/unloading ramps within the cartridge in
accordance with the present invention.
DET~TT ~n DESCRIPTION OF T~IE lNV~;r.LlON
Referring to the drawings wherein like numerals
indicate like elements throughout, there is shown in Figure 1
a disk cartridge 10 in accordance with a preferred embodiment
of the present invention. As shown, the disk cartridge 10
comprises an outer casing 12 having upper and lower shells
22, 24 that mate to form the casing. A disk-shaped storage
10 medium 14 is rotatably mounted on a hub 16 within the casing
12. An opening (not shown) in the bottom shell 24 of the
casing 12 provides access to the disk hub 16 in a
conventional manner. A head access opening 30 in the front
peripheral edge 20 of the disk cartridge 10 provides access
to the surfaces of the storage medium 14 by the read/write
heads of a disk drive. A shutter (not shown) can be provided
on the front peripheral edge 20 of the disk cartridge 10 to
cover the head access opening 30 in a conventional manner,
when the cartridge is not in use. In the present embodiment,
the disk-shaped storage medium comprises a flexible, or
floppy, magnetic disk, however, the invention is by no means
limited thereto. In other embodiments, for example, the
disk-shaped storage medium may comprise a rigid magnetic
disk, a magneto-optical disk or an optical storage medium.
Figure 2 is a perspective view illustrating the
interaction of the disk cartridge 10 of Figure 1 with an
exemplary linear actuator 31 of a disk drive into which the
cartridge 10 can be inserted. For convenience of
illustrating the present invention, the upper shell 22 and
disk-shaped storage medium 14 of the disk cartridge 10 are
omitted in Figure 2. An exemplary disk drive that
incorporates a linear actuator of the type shown in Figure 2
is described in greater detail in co-pending U.S. Patent
Application Serial No. 08/324,599, filed October 18, 1994,
entitled "Actuator for Data Storage Device", and in co-
pending U.S. Patent Application Serial No. 08/398,576, filed
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March 3, 1995, entitled "Movable Internal Platform for a Disk
Drive", both of which are incorporated herein by reference in
their entirety.
As shown, the bottom shell 24 of the disk cartridge
5 has an elongate groove 32 that forms a channel with a
corresponding groove (not shown) in the upper shell for
receiving a pair of opposing read/write heads 42, 44 mounted
on respective suspension arms 46, 48 of the exemplary linear
actuator. The suspension arms 46, 48 enter the cartridge 10
lo through the head access opening 30. According to the present
invention, head loading/unloading ramps are provided within
the cartridge 10 to guide the opposing read/write heads 42,
44 onto and away from the respective, opposite surfaces of
the storage medium (not shown) during head loading and
unloading operations. In the present embodiment, the head
loading/unloading ramps comprise first and second opposed
ramps 34 and 36, respectively.
As further shown in Figure 2, the first and second
suspension arms 46, 48 of the exemplary linear actuator have
respective wing members 50, 52 attached thereto, which in the
preferred embodiment, comprise elongate rods. It is
understood, however, that the wing members 50, 52 could take
any form and are by no means limited to the elongate rod
structures shown. As described below, these wing members 50,
52 ride on the first and second opposed ramps 34, 36 of the
present invention in order to guide the read/write heads 42,
44 onto and away from the respective surfaces of the storage
medium during head loading and unloading operations.
In use, as the read/write heads 42, 44 of the
linear actuator enter the head access opening 30 and approach
the edge of the storage medium (not shown), the wing members
50, 52 on the respective suspension arms 46, 48 ride up the
first opposed ramps 34, causing the heads 42, 44 to separate
so that they can pass on both sides of the storage medium.
Further travel of the suspension arms 46, 48 causes the wing
members 50, 52 to ride down the second opposed ramps 36,
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bringing the heads 42, 44 onto the respective surfaces of the
storage mea~um in a controlled manner.
Upon withdrawal of the suspension arms 46, 48 from
the disk cartridge, the wing members 50, 52 will ride back up
the second opposed ramps 36 to again separate the heads 42,
44. Further retraction of the suspension arms 46, 48 moves
the heads 42, 44 away from the storage medium and back down
the first opposed ramps 34. As the wing members 50, 52 ride
down the first opposed ramps 34 and begin to move back out of
the disk cartridge 10, the read/write heads 42, 44 are
preferably brought together onto a cleaning medium (not
shown) which cleans the heads while they are out of contact
with the storage medium. Such a cleaning technique is
described in co-pending U.S. Patent Application Serial No.
08/324,895, filed October 18, 1994, entitled "Head
Load/Unload and Cleaning in a Data Storage Device," which is
incorporated herein by reference in its entirety.
In the preferred embodiment, the first and second
opposing ramps are defined by first and second ramp members
38, 40 that are disposed near the head access opening 30 of
the disk cartridge on opposite sides of the head access
channel 32. Each ramp member 38, 40 has an upper portion
38a, 40a and a lower portion 38b, 40b separated by a
respective spacing 37, 39. The respective spacings 37, 39
receive the outer edge of the rotating storage medium (not
shown).
The read/write heads 42, 44 pass through the space
between the respective ramp members 38, 40, while the wing
members 50, 52 ride over the respective ramped surfaces 34,
36. The ramp members 38, 40 can be formed separately from
the outer casing 12 of the cartridge 10 and then mounted
within the cartridge 10 to either of the upper or lower
shells 22, 24. Alternatively, the first and second ramp
members 38, 40 can be formed integrally with either the top
or bottom shells 22, 24. In the present embodiment, the ramp
members 38, 40 are formed of plastic, although any suitable
material can be employed. In an alternative embodiment, a
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single ramp member can be employed on only one side of the
channel 32. However, two ramp members 38, 40 are preferable
to add stability to the head loading/unloading operation.
As the foregoing illustrates, the present invention
is directed to a disk cartridge having head loading/unloading
ramps disposed within the cartridge, as opposed to the prior
art technique of mounting such ramps in the disk drive.
Placement of the ramps within the cartridge allows the
movement of the read/write heads to be more accurately
controlled in relation to the vertical position of the
storage medium. It is understood that changes may be made to
the embodiments described above without departing from the
broad inventive concepts thereof. For example, while the
present invention is disclosed above in connection with a
linear actuator mechanism, the present invention could also
be employed in connection with a radial arm actuator.
Accordingly, the present invention is not limited to the
particular embodiments disclosed, but is intended to cover
all modifications that are within the spirit and scope of the
invention as defined by the appended claims.
